Biofuels, Wind Power, Solar Power, Geothermal, Hydro-electric energy, Wave power and Tidal barrages

Question 1

what are Biofuels?

Answer 1

created from plant products or animal dung, they can be burnt to produce electricity

Question 2

what do Biofuels do?

Answer 2

• they produce CO2 when they’re burnt, but the plants used will have absorbed a lot of CO2 while they were growing
• in some places, large areas of forest have been cleared to make room to grow biofuels, this leads to animals losing their natural habitats

Question 3

what is Wind turbines in Wind power?

Answer 3

• when the wind turns the blades, electricity is produced, they produce no pollution once they’re built
• they do no permanent damage to the landscape, if they are removed the area goes back to normal, they aren’t as reliable as other energy resources
• they don’t produce electricity when the wind stops, turbines are stopped if the wind is too strong to stop them from damage

Question 4

what are Solar cells in Solar power?

Answer 4

• they create no pollution once they’re built but a lot of energy is used to build them
• solar power only generates electricity during the day
• in sunny countries, they are a reliable source of energy, still fairly reliable in cloudy countries

Question 5

what is Geothermal power?

Answer 5

• it uses underground thermal energy stores of hot rocks below the Earth’s surface
• it can be used to generate electricity or to heat buildings
• its reliable because the hot rocks are always hot
• most geothermal power stations only have a small impact on the environment

Question 6

what is Hydro-electric power?

Answer 6

• uses falling water, involves building a big dam across valley, the valley is usually flooded which affects the environment
• water is allowed to flow out through turbines, which generates electricity, there is no pollution when running
• plants rot and release greenhouse gases which lead to global warming, animals and plants lose their homes

Question 7

what is Wave-Powered turbines in Wave power?

Answer 7

• turbines around the coast are turned by water waves and electricity is generated, there is no pollution
• they disturb the seabed and animals’ habitats
• they are unreliable as waves tend to die down when the wind drops

Question 8

what are Tidal barrages?

Answer 8

• they are big dams built across rivers and use the tides of the sea
• water passes through the turbines and generates electricity, the amount generated changes with the tides
• they are reliable as we can predict the tides but they changed the habitat of wildlife and often fish are killed in the turbines